If you like the ocean and it's a nice day then:

For shopping go to Venice Beach. Between the boardwalk and the pier, you'll see every flavor of character California has to offer and find some fun shops to peruse.

While you're on PCH, drive up to Neptune's Net north of Malibu for lunch. Fresh seafood every day and a great view of the ocean. Stop by Zuma and Westward beaches where they filmed all the Baywatch shows.

For the evening head down to the Santa Monica pier and the clubs on Colorado & Santa Monica Blvd. There's a great Irish Pub on SM blvd but I forget the name.